Instead of asking ourselves what on earth went on in this week's episode, it would be much quicker to summarise what didn't happen. Just when you thought the series might take an upswing towards sensible, it headed into manic plot overdrive, giving us more back story and crazed exposition than a drawerful of Aunt Blanche's Sapphic correspondence.

So Aunt Blanche (Alex Kingston) turned out to be a lesbian. Who knew? Surely anyone who recognises the period drama shorthand which has been telegraphed from the first episode. All the signs were there: inquiring mind, no makeup, Virginia Woolf-type clothes, comfortable shoes...

And lo, here comes Portia (Emilia Fox), the author of The Golden Blaze, a swoonsome novel detailing their romance amongst the archaeological ruins of the Egyptian desert! "Rosalind's body was being filled with spices..." This being BBC1 we did not really get to see any major league spice-filling. Just some dishevelled hairstyles. 165 Eaton Place was ablaze with scandal for, ooh, all of about five minutes – one dinner was even cancelled! – until they moved onto the next dozen dramas.

Lady Persie (Claire Foy), meanwhile, is pregnant by her Nazi lover and has become an ardent fan of gin, hot baths and vigorous horse-riding. She later answers an advert in the paper for a backstreet cure for "menstrual irregularity." Sir Hallam (Ed Stoppard), her brother-in-law and erstwhile kissing companion, appeared to head randomly to Berlin to confront Friedrich the Nazi who basically shrugged, "She slept with the entire party. Not my problem."

The downstairs plot offered no more sanity. Beryl (Laura Haddock) decided to fight for her rights when she and Eunice (Ami Metcalf – lovely actress) were given extra household duties, despite Mr Pritchard's insistence that "This is Belgravia. Not Leningrad." The relationship between Spargo the chauffeur (Neil Jackson) and Beryl did not move forward, disappointingly. And the war? Hello? What happened to the war? It's still 1939 but no one seemed to notice this week that there might be one or two little things going on in the outside world.

Things which infused us with a joy equal to the fuzzy peach glow of Lady Agnes's peignoir

I'm grasping at straws here. The wardrobe of Lady Agnes (Keeley Hawes) brings no end of joy. Her green Robin Hood hat for her visit to Miss Buck was adorable, as was the dress with the swallows on it. And I did rather enjoy Lady Agnes's self-improving foray into the world of Lavinia Godfrey, Lady Prunella and the Women's League of Health and Beauty. "No point in all this kicking and marching if the nethers don't get aired!" "Chin up, Petronella!" "If anyone's perspiring, there's some eau de cologne on top of the piano!"

The most beautiful moment of this episode, though, was Mr Pritchard's face at the breakfast table as the words "unnatural female passions" emerged from Sir Hallam's mouth. The most fabulous mixture of envious delight and loyal, butlerly discretion.

Things that bathed us in a misery reminiscent of the gassing of Solomon the monkey

Where to start. Where was the comedy? Where were Mr Pritchard's wonderful one-liners? Where were simple, understandable plot lines? One is trying so hard to enjoy this programme and immerse oneself in it. There are some great performances. The atmosphere and the costumes are beautiful. But somehow it is not coming together. The script is all over the place, most of the scenes are about 90 seconds long and there is just too much going on. Even the period detail – surely Upstairs's greatest strength – is slipping a little. I almost threw a matted rabbit's foot at the screen when the BBC announcer came on at the end, talking about Herr Hitler. It sounded like Victoria Derbyshire reading the football results on Radio 5 Live. This is 1939, for heaven's sake. Dub in some clipped vowels!

The Lady Maud Holland tribute moment

It was up to Sir Hallam to raise the spectre of the departed Lady Maud (Eileen Atkins) – his mother and Blanche's (half) sister. Although I'm not so sure she would have been as horrified as he claimed by Blanche's "tendencies". Sir Hallam was right about one thing, though. The house has indeed been in a complete mess since Lady Maud passed away. But less because of her death and more because of a screenplay that tries to make 573 things happen simultaneously.

"Could we get in more food and drink references in if we tried?"

Oh, misery. This week one could not even distract oneself by counting food references. We had a measly grapefruit with the last cherry on it, rejected by Lady Percy as she pined for Friedrich the Nazi. We had one solitary Garibaldi for Beryl to sustain her during her appeal to the union representative about conditions in the house. And things were getting really desperate by the time Mrs Thackeray mentioned the "potato peel in the pocket of the peignoir". Oh, and I'm nearly forgetting the tin of Huntley & Palmer Afternoon Tea Biscuits for being The Most Helpful Boy in the House. Please, spare us.

This week it was all about drink. And goodness knows this series is enough to drive you to it. On screen we had whisky to anaesthetise Lady Agnes from the idea of Cousin Blanche as an "invert'. Gin to help Lady Percy forget Friedrich (and ideally to bring on a miscarriage). And sweet sherry for Mrs Thackeray, if only the newly politically enlightened Eunice wasn't refusing to bring it to her during her break. Off screen I felt like downing meths.

And The House of Idiot memorial award for most randomly thrown-in example of period detail goes to ...

Oh dear, we're back to the Mitsouko and the Shalimar. When Lady Agnes visits Miss Buck (Jean Marsh) in the convalescent home. The erstwhile housekeeper notices that the lady of the house has changed her perfume. I love the idea of this detail, that the servants were so attached to their overlords that just the scent of them grew familiar and reassuring ... but in the execution why does it feel so clumsy and forced?

Next week:

Johnny the valet becomes a boxer. Lady Persie flirts some more with Hallam. And even though I am losing the will to live, I will tune in just to see Caspar Landry (Michael Landes) and his long-promised rumba.